Buggy code:
public class ElementImpl implements Element { protected Element e ; public ElementImpl ( ) { } public ElementImpl ( String tagName ) { } public ElementImpl ( com . google . gwt . dom . client . Element e ) { } protected ArrayList < Element > nodesToElements ( NodeCollection < com . google . gwt . dom . client . Element > elements ) { } @ Override public void setTarget ( Object target ) { } @ Override public Element attr ( String name , String value ) { } @ Override public Element css ( String property , String value ) { } @ Override public Element css ( String property , String value , Unit unit ) { } @ Override public Element html ( String html ) { } @ Override public List < Element > children ( ) { } @ Override public String attr ( String name ) { } @ Override public String css ( String property ) { } @ Override public String html ( ) { } @ Override public String text ( ) { } @ Override public Element text ( String html ) { } @ Override public String tag ( ) { } @ Override public List < Element > query ( String selectors ) { ArrayList < Element > elements = new ArrayList < Element > ( ) ; <START_BUG> for ( com . google . gwt . dom . client . Element element : com . google . gwt . query . client . GQuery . GQuery . $ ( e ) . children ( selectors ) . elements ( ) ) { <END_BUG> elements . add ( new ElementImpl ( element ) ) ; } return elements ; } @ Override public Element addClassName ( String className ) { } @ Override public Element removeClassName ( String className ) { } @ Override public Element toogleClassName ( String className ) { } @ Override public String getClassName ( ) { } @ Override public boolean hasClassName ( String className ) { } @ Override public int absoluteBottom ( ) { } @ Override public int absoluteLeft ( ) { } @ Override public int absoluteRight ( ) { } @ Override public int absoluteTop ( ) { } @ Override public int clientHeight ( ) { } @ Override public int clientWidth ( ) { } @ Override public String dir ( ) { } @ Override public List < Element > elementsByTagName ( String name ) { } @ Override public Element first ( ) { } @ Override public Element last ( ) { } @ Override public String id ( ) { } @ Override public String lang ( ) { } @ Override public int offsetHeight ( ) { } @ Override public int offsetLeft ( ) { } @ Override public Element parent ( ) { } @ Override public int offsetTop ( ) { } @ Override public int offsetWidth ( ) { } @ Override public boolean propertyBoolean ( String name ) { } @ Override public double propertyDouble ( String name ) { } @ Override public int propertyInt ( String name ) { } @ Override public Object propertyObject ( String name ) { } @ Override public String propertyString ( String name ) { } @ Override public int scrollHeight ( ) { } @ Override public int scrollLeft ( ) { } @ Override public int scrollTop ( ) { } @ Override public int scrollWidth ( ) { } @ Override public int tabIndex ( ) { } @ Override public String title ( ) { } @ Override public boolean hasAttribute ( String name ) { } @ Override public boolean hasTagName ( String tagName ) { } @ Override public Element removeAttr ( String name ) { } @ Override public Element replaceClassName ( String oldClassName , String newClassName ) { } @ Override public Element scrollIntoView ( ) { } @ Override public Element setClassName ( String className ) { } @ Override public Element dir ( String dir ) { } @ Override public Element id ( String id ) { } @ Override public Element lang ( String lang ) { } @ Override public Element propertyBoolean ( String name , boolean value ) { } @ Override public Element propertyDouble ( String name , double value ) { } @ Override public Element propertyInt ( String name , int value ) { } @ Override public Element propertyObject ( String name , Object value ) { } @ Override public Element propertyString ( String name , String value ) { } @ Override public Element scrollLeft ( int scrollLeft ) { } @ Override public Element scrollTop ( int scrollTop ) { } @ Override public Element tabIndex ( int tabIndex ) { } @ Override public Element title ( String title ) { } @ Override public void scrollWidth ( int scrollWidth ) { } @ Override public Element insert ( Element element , int index ) { } @ Override public Element add ( Element element ) { } @ Override public Element remove ( Element element ) { } @ Override public Element remove ( int index ) { } @ Override public Element removeFromParent ( ) { } @ SuppressWarnings ( "unchecked" ) @ Override public < T extends Element > T from ( Element e ) { } @ Override public Element insert ( Element element , Element beforeElement ) { } @ Override public HandlerRegistration click ( final EventHandler handler ) { } @ Override public HandlerRegistration dblclick ( final EventHandler handler ) { } @ Override public HandlerRegistration blur ( final EventHandler handler ) { } @ Override public HandlerRegistration focus ( final EventHandler handler ) { } @ Override public HandlerRegistration change ( final EventHandler handler ) { }

Fix:
for ( com . google . gwt . dom . client . Element element : com . google . gwt . query . client . GQuery . GQuery . $ ( e ) . find ( selectors ) . elements ( ) ) {